The chairman and largest investor in Sears Holdings is offering to buy the retailer out of bankruptcy — including 500 of its remaining stores — in what may amount to the chain’s last hope to survive its precipitous decline.

“Sears is an iconic fixture in American retail and we continue to believe in the company’s immense potential to evolve and operate profitably as a going concern with a new capitalization and organizational structure,” Lampert said in a letter.

“Our proposed business plan envisages significant strategic initiatives and investments in a rightsized network of large format and small retail stores, digital assets and interdependent operating businesses.”

Lampert said the acquisition would keep 50,000 Sears employees working.

He said the deal would include 500 stores, which covers essentially all of the locations Sears has not identified for closure. The deal would include Sears and Kmart stores.

The deal would also include the Kenmore appliance and DieHard tool brands, key real estate and the company’s inventory and receivables.

Lampert described his offer as worth about $4.6 billion “in total consideration.” He said the price would include debt to be issued by Sears, “a credit bid” of about $1.8 billion and the assumption of certain liabilities.

In recent years, Lampert’s ESL hedge fund has loaned Sears more than $2.4 billion in financing. So he could lose a fortune if Sears is forced to liquidate or stick creditors with steep losses.

But critics have also accused him of structuring his deals to ensure he gains access to key assets in the event of the retailer’s demise. He was also earning hundreds of millions annually in Sears debt payments before the retailer’s bankruptcy.